Importance

Loading Importance Indicators...

Abstract

A natural gas feed stream containing significant quantities of nitrogen can be increased to a content of greater than 95 percent by volume of natural gas, and preferably greater than about 98 percent, by passing the natural gas feed stream sequentially through at least four adsorbent beds which are cycled through six phases comprising an adsorption phase to adsorb natural gas, a recycle phase to remove feed gas from the voids in the adsorbent bed and nitrogen from the adsorbent by the passage of a depressurization gas therethrough to produce a recycle gas, a depressurization phase to reduce the adsorbent bed pressure to about ambient and to produce the depressurization gas, an evacuation phase where the pressure in the adsorbent is further reduced and an enriched natural gas product stream recovered, a pressurization phase where the pressure in the adsorbent bed is increased using nitrogen gas from a bed in an adsorption phase, and further pressurizing the adsorbent bed in a recycle feed pressurization phase by the flow of the recycle gas therein.

Loading the Abstract Image...

First Claim